MELOCEINIDJE. 



265 



Arms biserial. Dorsal cup subturbinate 



Arms- uniserial; dorsal cup depressed; interbracMals 



few, longitudinally arranged 



C. Basals large, probably three, anchylosed. 

 a. Costals two, the first quadrangular. 

 Interhracliials few. 

 Dorsal cup subcylindrical ; basals and radials very large, 



distichals small ; arms unknown 



Calyx depressed-subglobose; basals small, interbracMals 

 few, the first extremely large. Arms biserial and gen- 

 erally branching. Slit-like respiratory pores at the 



sides of the ambulacral openings 



h. Costals one; pentangular. 



Otherwise resembling Dolatocrinus 



InterbracMals numerous, basals forming an inverted cup 



Patelliocrinus.^ 



Allocrinus. 



Centrocrinus. 



Dolatocrinus. 



Stereocrinus. 

 Jfadrocrinus. 



Geological and Geographical Distribution. 

 Number of known species. 



(Open figures indicate American ; those marked ( ), European.) 



1 



g 



Formation. 



Melocrinid^. 



American. 



Approximate 



European 



Equivalents. 



Melocrinites. 



Dolatocrinites. 



I 

 3 



.9 



'f-i 

 P, 



(3) 



i 



2 



3(1) 



Pi 

 P^ 



(1) 



CO 



o 



3(9) 

 1(7) 



2(3) 

 .5(4) 



11 



(23) 



t 



6 



CO 



§ 



2 



i 



.9 



9 

 o 



(6) 



03 

 PS . 



PI 



1 



(7) 



CO 



PS 



a 

 2 



.9 



PI 

 6 



1 



.9 

 *G 



o 



1 



ft 



8 

 5 



_9 



1 



a, 



2 



IB 



.9 



2 

 2 



1 



o 



Hamilton. 



Up. Devon. 







Up. Helderberg. 



Eifel. 





Oriskany. 







Low. Helderberg. 



Grauwacke. 





Niagara. 



Wenlock. 

 Bohemia. 

 Gotland. 







Hudson River. 





4 









(1) 



Trenton. 





3 



7 



2 

 2 



1 



1 

 (3) 



5 



(1) 



6 



2 



(6) 



(7) 



2 



1 



13 



2 



Total species 95 j .J^, 



* Excluding F./ulmimfus and P. duplicatm, winch probably belong to Mariacrinus, and P. chiastodac- 

 and P. pinnulatus, which are young specimens. 



34 



